Element-selective observation of photo-induced magnetization dynamics in ferromagnetic materials using synchrotron radiation x-rays

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K23430
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0202:Condensed matter physics, plasma science, nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: Institute for Molecular Science
• Principal Investigator: Yamamoto Kohei 分子科学研究所, 物質分子科学研究領域, 助教 (30844823)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Keywords: 磁性

Outline of Final Research Achievements

The control of magnetization by light has attracted strong attention not only from the viewpoint of science but also from the application to recording media. In particular, photo-induced magnetization reversal has been reported in systems containing different magnetic elements, and element-selective measurement of photo-induced transient states is important. We have established a magneto-optical Kerr effect measurement system at the soft x-ray free electron laser beamline SACLA BL1 (SXFEL) by matching the optical energy to the absorption edge of the material, and have been conducting various experiments. We have already succeeded in the element-selective measurement using Co/Pt thin films. We have already succeeded in the element-selective measurement of the effect using Co/Pt thin films. We have also conducted experiments on the excitation laser dependence of the effect and clarified their elemental dependence.

Free Research Field

放射光

Academic Significance and Societal Importance of the Research Achievements

人類の扱う情報量は計算機や通信機の技術の発達により増大し続けている。それらの情報を保存する主要な媒体の一つが磁性体である。そのため磁性体の磁化の高速かつ高効率な制御法の開発は重要であり、光学的な制御法が期待されている。その意味で光と磁性体との関連を明らかにすることはそれらの開発に寄与し得る。われわれは特に、複数の磁性元素を含むような磁性体において、それらの光によって誘起される過渡的状態を超高速かつ元素選択的に測定する手法を確立し、それを用いて磁性体の元素依存的なふるまいを見出した。